Illuminated displays

ABSTRACT

An animated illuminated colored advertising display including a display board built up of individual lighting units each comprising a group of lamps, giving primary colors, behind a translucent screen, and control equipment in the form of a matrix of photoelectric cells equivalent in numbers and positions to the lamps in the display boards and each controlling the switching of a respective lamp, together with a cinematograph projector for projecting on to the photocell matrix a black and white cinematograph picture to influence the photocells.

United States Patent Inventors Anthony Powell Bideford; Peter Dunstan Renwick Adams, Ware, both of England Appl. No. 775,044 Filed Nov. 12, 1968 Patented Dec. 28, 1971 Assignees Seemark Switches Limited Bldelord, Devon, Adams Huntley Associates Ware, England ILLUMINATED DISPLAYS 6 Claims, 12 Drawing Figs.

0.8. Ci 340/339, 40/130 1., 340/324 R, 340/334, 352/131, 353/122 Int. Cl 609i 9/32 Field of Search. 352/131; 340/334, 339; l78/7.5 D, 7.3 D, 6; 40/1301, 132 C, 130 L, 125 L W wu l [56] References Cited UNITED STATES PATENTS 3,283,318 11/1966 Bramer 340/339 1,880,026 9/1932 Singerman 40/132 2,154,110 4/1939 Parks 340/339 3,273,140 9/1966 Foster 340/334 Primary Examiner- Louis R. Prince Assistant Examiner-Denis E. Corr Att0rney-Dowel1& Dowell ABSTRACT: An animated illuminated colored advertising display including a display board built up of individual lighting units each comprising a group of lamps, giving primary colors, behind a translucent screen, and control equipment in the form of a matrix of photoelectric cells equivalent in numbers and positions to the lamps in the display boards and each controlling the switching of a respective lamp, together with a cinematograph projector for projecting on to the photocell matrix a black and white cinematograph picture to influence the photocells.

Patented Dec, 28, 1911 3,631,461 7 Patented Dec. 28, 1971 3,631,461

8 Sheet 2 'Patented Dec. 28, 1971 7 3,631,461

8 Sheets-Sheet 5 I nlor) I MS QVYJW By 9M% Patented Dec. 28, 1971 3,631,461

8 Sheetsheet 4 Pam B gmm Patented Dec. 28, 1971 3,631,461

8 Sheets-Sheet 8 Patented Dec.. 28, 1971 3,631,461

8 Sheets-Sheet 6 lI/IlI/I/I/l/lll/l/[U l-QMLQ Patented Dec. 28, 1971 7 3,631,461

8 Sheets-Sheet 7 00+ y com/10 "2 3 4 5 6 PONR Patented Dec. 28, 1971 3,631,461

8 Sheets-Sheet 8 ILLUMINA'I'ED DISPLAYS This invention relates to illuminated displays, and particularly but not exclusively to animated displays for advertising and like purposes.

It is known to provide, for example on an external wall of a building, an illuminated display sign comprising a very large number of individual lamps arranged in a mosaic or matrix of columns and rows so that different displays can be set up by selective illumination of the lamps. However, the usefulness of such signs is considerably limited by comparatively slow switching, poor definition and the lack of adequate facilities for producing displays in rapidly changing colors. Also such signs have hitherto been costly when considered in relation to the limited facilities they afford.

According to the invention, there is provided an illuminated display system including a display equipment and a control equipment in combination, the display equipment comprising a plurality of lighting units each with an individual translucent screen and placed with their screens together building up a substantially continuous display area, with electric lamps behind the individual screens in an arrangement such that each screen can be illuminated selectively in a choice of colors without causing illumination of its fellows, and the control equipment comprising a matrix of electronic components that can be rapidly selectively activated to give individual output control signals for switching the lamps and selecting the colors, there being at least one such component allotted to each lamp with an associated transistorized switching relay for switching the lamp in response to the output signal of that component.

In one form, the electronic components can be a matrix or mosaic of photoelectric cells selectively activated by projection thereon of a light and dark image from a slide or film projector. The use of cinematograph film gives rapid changing of the projected image and therefore animation of the display. However, it is also possible for the electronic components to take the form of one or more matrix stores into which the control information for the display is read from, for example, a magnetic tape record.

Color illumination may be obtained either by switching a plurality of lamps in each lighting unit, provided with differently colored static filters, or by moving the filters in front of a single lamp; In the former case particularly, rapid switching is required for satisfactory animation and whereas it has been a problem hitherto to achieve at low cost a rapidly switching device that is reliable over a great number of operations, a novel form of relay will be hereinafter described which is satisfactory in these respects and is small and inexpensive so that capital cost and replacement are not serious considerations.

In the instance of control by a photocell matrix, there will be a photocell corresponding to each lamp, or each filter and each lamp in the case of moving filters, and it is necessary to arrange, in the production of any desired display, that the image on each projected film frame or transparency is such as to permit transmission of light at those elements or regions where the light will fall on to photocells corresponding to the lamps or filters that are required to be switched on or operative to create the desired display and to prevent light transmission on to those photocells corresponding to lamps or filters that are to remain switched off or inoperative. This can be achieved by means of images taking the form of different arrays of transparent spots set in an opaque background; any convenient coding scheme for the spots, correlated with the relative placings of the individual photocells in the matrix, may be employed.

Various ways of carrying the invention into effect will now be described in more detail by way of example, reference being had to the accompanying drawings in which:

FIG. I shows part of a display sign in front elevation,

FIG. 2 is a side elevation of the same part of the sign,

FIG. 3 is a side view of one individual lighting unit of the sign,

FIG. 4 is a pictorial diagram showing the general configuration of a module consisting of three lighting units, as seen from the back,

FIG. 5 is a diagram to indicate the placing of color filters in an individual lighting unit,

FIG. 6 is a diagrammatic view of part of the back of a lighting unit,

FIG. 7 is an elevation of a relay for use in the control equipment,

FIG. 8 is an elevation in the direction of the arrow 8 of FIG. 7,

FIG. 9 is a plan view seen in the direction of the arrow 9 of FIG. 7,

FIG. 10 is a diagrammatic side view of an alternative form of lighting unit,

FIG. 11 is a circuit diagram of the control arrangements for the unit of FIG. 10, and

FIG. 12 illustrates a film camera and photocell control matrix arrangement such as may be used for controlling the display sign of FIGS. 1 to 9. In the example illustrated in FIGS. 1 to 6, the illuminated sign is mounted on an end wall II of a tall building (FIGS. 1 and 2) and provides a total display area 10 which is approximately feet high and 60 feet wide. This area is formed by the screens 12 of 4,608 lighting units arranged in 96 rows and 48 columns and each approximately l5 inches high and I5 inches wide.

Each lighting unit of the sign includes a casing 13 which is constructed of pressed metal and is formed with top, bottom and opposed sidewalls and is open at the front and rear. The casing is generally rectangular as viewed from the front but over the major part of its depth decreases in height and width from front to rear of the unit, as best seen in FIG. 3.

At the front of the casing is the rectangular screen 12 which is made of a translucent plastics material and is dished to provide increased strength. The screen is formed with rearwardly extending peripheral parts 14 which are fitted into the front end 15 of the casing 13, formed of suitably enlarged height and width for the purpose of receiving the screen.

Fitted into the rear of the casing is an illuminating assembly 16 which includes red, yellow, green and blue filters l7, l8, 19, 20 arranged in the four quarters of a square when seen from the front of the casing, as will be clear from FIGS. 4 and 5. A frustopyramidal lamp reflector 21 is a releasably secured to the rear of each filter (FIGS. 2 and 3) and a lamp is mounted within each reflector. To achieve a satisfactory color balance on the screen the lamps associated with the blue, red, green and yellow filters are suitably I00 watts, 75 watts, 75 watts and 40 watts, respectively.

The filters 17 to 20 are arranged on the assembly so that each outer edge of a filter is disposed forwardly of the opposed inner edge, and the axis 22 of each lamp reflector 21, when projected forwardly, extends through the center point 23 of the screen 12 at the front of the casing (FIGS. 3 and 6). Light from each lamp is therefore directed towards the center of the screen 12 and the intensity of illumination from each lamp is substantially uniform over the whole area of the screen. The walls of the casing 13 and the reflectors 21 serve to prevent light from the four lamps of one unit from reaching the screens of adjacent units.

For ease of assembly into the sign the units are secured together in groups of three, as illustrated in FIG. 4, the casing of the central unit in the group being welded along opposed forward edges thereof to the respective casings of the two flanking units which, when the group is in its mounted position, are respectively disposed above. and below the central unit. A mounting lug 24 (FIG. 3) is secured to each of the opposed sidewalls of the casing of each unit and has a stud 25 welded to it with the threaded end of the stud extending rearwardly therefrom. Similar mounting lugs are provided on the top wall of the casing of the uppermost unit in a group of three and on the bottom wall of the casing of the lowest unit of the group.

For supporting the units a grid formed of 49 upright bars which extend from top to bottom of the sign and 33 horizontal bars which extend across its width is provided on the end wall of the building. The upright bars are horizontally spaced at approximately 45 inches and the horizontal bars are vertically spaced at approximately l5 inches. The grid therefore defines a series of rectangular areas each of which corresponds to the combined area of the three screens of one of the above-mentioned groups of three units.

Each bar 26 of the grid is of T-section and is arranged with the arms 27 of the T parallel with the end wall of the building and the stem 28 thereof projecting forwardly therefrom. To mount the lighting units on the grid each group of three units is held up in front of the grid, in register with one of the abovementioned rectangular areas between the grid bars, and is then moved rearwardly so that the mounting studs 25 thereon are engaged in respective holes in the T anns of the bars defining that area. The three-unit group is then secured to the bars 26 by nuts 29 placed on the threaded, rearward ends of the studs.

With the units in their mounted positions the front edge of each casing 13 is substantially in contact with the front edges of the casings of the four units adjacent thereto. The screens 12 of the units therefore fonn an almost unbroken area of translucent material which can be selectively illuminated in different colors by the lamps behind. The lighting of any one lamp of a particular unit will cause the small area of the sign constituted by the screen of that unit to be illuminated with one of the four primary colors; other colors are produced by the lighting of difierent selections of two of the four lamps, white illumination being produced if blue and yellow lamps are alight simultaneously.

Referring now to FIG. 12, to form a predetermined display on the sign a specially processed film 80 or slide transparency is projected on to a lamp-control matrix 81 in a control room within the building. Each slide or film frame 82 may be divided up into four quarters 83 and upon these four quarters are four images formed by the red, yellow, blue and green contents, respectively, of the portion of the display allotted to that frame, i.e., each image is adapted to transmit light through those areas thereof which correspond to the areas of the display containing the primary color associated with that image.

Within the area of the lamp-control matrix 81 upon which each quarter of the film frame is projected are 4,608 photoelectric cells 84 arranged in 96 rows and 48 columns, corresponding to the rows and columns of units in the sign. This gives a total of 192 rows and 96 columns for the four quarters of the frame. Each photoelectric cell is arranged, upon energization to operate a relay switch (FIGS. 7 to 9) which is connected in circuit with a single lamp in the sign. Lights from any particular small area of one of the four images on the film frame 82 falls on an appropriate photoelectric cell 84 in the matrix 81 to cause energization of the individual lamp in the sign which is one of the four in the unit corresponding to that color image.

Assuming, for instance, that a particular small part of the display is to be orange, those areas of the red and yellow images on the film frame 82 which correspond to that particular part are transparent. Light is therefore projected through two transparent areas on to the control matrix 81 and the as sociated photoelectric cells and relays are energized. The two lamps behind the red and yellow filters in the unit of the sign which corresponds to the particular part of the display are 1' therefore lighted and the screen of this unit is illuminated from the rear with a mixture of red and yellow light, producing an evenly diffused orange light over the whole area of that screen. Each unit is controlled in similar fashion so that any desired display can be reproduced on the sign.

If static transparencies are used the display appearingupon the sign is changed by changing the transparency in the projector, and means may be provided for effecting such a change automatically at predetermined intervals of time. Alternatively, programs of different and, if desired, animated displays can be obtained by using a moving film in a cinematographic projector 85, which may be a loop film for automatic repetition.

To make a suitable film, the subject may be filmed four times with appropriate color filters in the camera optical path. Then a master film can be printed, with all four color element images presented as one frame in a dimensionally displaced form. Alternatively, the technicolor process may be employed, or color splitting of the picture may be achieved by the use of dichroic mirrors, followed by printing of the four colorseparated images in displaced relationship on to one frame as before.

This system calls for fairly accurate registration both in printing and in projection but provided the master film images are black and white without greys (the greys are removed by photographic processing) position color switching can be achieved.

However, it will be understood that it is not at all necessary that there should be four recognizable color-separated black and white images on the transparency or film frame through which light is projected on to the photocell matrix for the purpose of controlling the lamps of the sign. Since the activation or nonactivation of any one photocell depends simply on whether there is a go or no go condition for projected light at the particular area or spot on the film appertaining to that particular photocell, the film images may take the form of a changing pattern of dots or spots. Moreover, there is no need for the pattern of dots representing any one color-separated image to be preserved in a particular ordered array or to be positionally displaced as a whole from the other image dot patterns on the same film frame; any desired scrambling" of the clot patterns may be employed to form a composite four-color coded pattern providing the photocells are correspondingly coded in regard to their connections to the sign lamps such that the image is unscrambled when it is thrown upon the sign.

In many instances the film frames or transparencies will be produced from studio art work instead of by filming of an actual subject, in which case it will often be simpler to create a dot pattern, coded or otherwise, rather than make cartoonlike drawings of the images as they are required to appear on the sign. One possibly convenient arrangement is to group in fours the dots representing the four primary color lamps of the individual lighting units of the sign, the photocells being likewise grouped as regards their control of the lamps so that the photocells are not in four positionally-displaced color separated banks but are more nearly in occupation in the matrix of positions corresponding to the actual positions of their respective lamps in the sign.

To control the lamps, the photocells in the matrix are wired to individual transistorized switching relays similarly arranged in rows and columns. In addition to the photocell matrix and relays it is advantageous to provide in the control room a panel of small lamps wired to indicate which of the lamps in the sign are lit at any instant, thereby facilitating the replacement of failed lamp bulbs. A further panel of neon bulbs can be employed, if desired, to indicate relay operation.

The number of relays required is large being equal to the number of photocells and lamps in the sign. It is therefore important to provide a relay that will switch reliably and rapidly under the control of a photocell but is nevertheless simple and inexpensive to make. One such arrangement is shown in FIGS. 7 to 9. The relay unit consists basically of a printed circuit panel 30 with a relay coil bobbin 31 mounted on it in such manner that the circuit panel becomes one end of the bobbin, the ends of the coil being fed through holes 33, 34 in the printed circuit panel and being connected directly to the printed circuit elements 32 on the panel underside.

An L-shaped mild steel sheet member 35 has one limb extending across the top of the bobbin and riveted to the mild steel bobbin core and the other limb extending down alongside the bobbin and into a slot 36 in the panel 30 where it is secured to the panel. The lower edge of this latter limb of the member 35 extends obliquely a short distance below the panel 30, as at 37, and provides a pivot for the relay armature 38 which is another mild steel sheet member having an arm portion 39 lying close under and substantially parallel to the panel and passing across the end of the core of the relay bobbin which projects through the panel at 40. At one end the arm 39 has a switching tongue 41 carrying a movable contact 42 which operates between fixed contacts 43, 44 on the panel30 that are connected to respective printed terminals 45, 46. The movable contact 42 is itself connected through the arm 39 and by a wire 47 to a further printed" terminal 48. The opposite end of the arm 39 is folded around the projecting edge 37 of the member 35 and then projects up through the slot 36 to provide a limb 49 on which bears a leaf spring 50, anchored to the member 35, for urging the armature contact 42 toward the lower fixed contact 44. A tang 51 on the projecting edge 37 of the member 35 passes through an aperture in the folded part of the armature 38 to prevent relative lateral displacement.

The remaining components of the relay unit are a transistor 52, a capacitor 53 and a resistor 54, all supported from the panel 30, on the same side thereof as the bobbin 31, by their respective lead wires 55, 56, 57 which pass through the panel to be connected to the printed circuit elements 32.

By reducing the material in the magnetic circuit to a minimum, and using mild steel for this purpose, a small lowpriced relay is obtained which is nevertheless sensitive and well adapted to photoelectric cell control. Relays made in this way can readily be mounted in rows on a frame by means of their printed circuit panels.

While the photocells in the matrix may be separate units mounted as close together as possible, it is advantageous to produce a mosaic of cells by the use of printed circuit techniques. Boards are made up of a standard size, carrying a series of parallel commoned circuit lines. Suitably spaced between these lines are holes surrounded by conductive connection areas. Small strips of cadmium sulfide material (or other photosensitive material) are placed to bridge the common lines and the connection areas. Individual wires pass through the holes to connect to each element. Alternatively, connecting devices may be fitted to allow the use of special I connectors, i.e., to provide for a spring contactarrangement or solderless wire connections. The whole board is then suitably protected by lacquer or other means.

The advantage of this mosaic is that a very large number of cells can be packed into a small space and if standard boards are used these can be overlapped to make up mosaics of any desired size to give the picture resolution required.

Although a sign has been described and illustrated in which four separately switched primary color lamps are fitted in each lighting unit, other numbers of lamps may be employed. If a three-color system is used, a full chromatic range cannot be produced; thus, for example, blue, yellow and red lamps will not produce green. This may be partially overcome by fitting a separate green lamp in each unit and arranging a logic circuit so that this lamp lights only if all the other three lamp relays are activated. The green lamp can, under this condition, be arranged to light in place of the three colored lamps. If each such logic device is fitted to its unit in the display sign no addi-.

tional wiring is required. This provides, in effect, a four-light system with a 25 percent saving in external wiring.

By using rectifiers a further saving in wiring may be made. This entails running the lamps on half-wave rectified AC, the supply for two lamps of opposite polarity being conveyed through the same leads.

For smaller sizes of sign than that illustrated, or greater resolution, it is possible to reduce the size of the individual lighting units considerably. A 5 inch square unit is practicable with four lamps giving the four primary colors. Such a unit can be readily made consisting basically of mouldings in plastics materials and it is preferred that the switching relays for the lamps should be mounted on the backs of the units rather than in the control room. Constructing each unit in the form of a pullout module will considerably assist maintenance.

The system already described functions satisfactorily. Nevertheless, a modified system will now be described, with reference to FIGS. and 11, which is intended to reduce installation and operation costs and possibly also manufacturing costs.

With this arrangement again current switching is carried out within the display sign, and as a result only small conductors are required to be taken back to the controller. In addition a coding system can be used enabling, say, four colors in each light unit to be controlled by one isolated wire and one wire common to all the light units. This means that in addition to reducing the size of the conductors to a minimum their total number is greatly reduced.

One lamp only is fitted to each light unit and this lamp produces all four colors. This greatly reduces the overall number of lamps. The lamp could be switched on shortly before the unit was required to provide light but would not be switched to provide color change; it could be switched off again immediately after the end of a display sequence. if a series of display sequences followed each other rapidly the light could be left on until they had finished.

Under these conditions it is unlikely that more current would be used than if the lamp were repeatedly switched and the life of the switching contacts would be increased greatly.

The fact that the system can be operated without rapid lamp switching enables low-voltage high-efficiency lamps to be used to provide good illumination with less current consumption. This type of lamp is not practical if rapid switching is required because of the length of time taken for the filament to heat and cool. in this system there is still only one switching relay per lamp so not only do the contacts (individually) have increased life but also there are fewer of them.

Basically, the system operates as follows (assuming a fourcolor arrangement is required).

The photocell matrix is arranged as before but one additional photoelectric cell is used for each light unit.

As previously, film is prepared so that each element of detail is represented as a translucent dot (or dots) so arranged that when projected onto the photoelectric cell matrix the light transmitted will fall directly upon the correct color (or mixture of colors) in the correct position on the display.

However, in addition a further dot is printed on the film for each element of detail. This dot is arranged to appear a few frames in advance of the color information and when projected onto the photocell matrix will fall upon the additional photocell of the respective light unit. The purpose of this extra spot is to switch on the light unit so that it is ready to receive the color information. Once switched on the lamp can be maintained on by color information (without the extra dot) but if it is desired to keep the lamp on between rapidly occurring sequences this extra dot must appear when there is no color information present.

Referring to FIG. 10, the lamp 58 has a reflecting mirror 59 behind it and is arranged so that its light passes through a condenser 66, an aperture 60 and a lens 61 to fall upon the translucent screen 62 of the light unit. The lamp is switched on and off by a lamp relay 67. When the lamp is on and no color information is being received the aperture 60 is obscured by a shutter 63. The four-color information photoelectric cells in the control matrix are connected to respective electromechanical servomechanisms 64 each of which when energized withdraws the shutter 63 and places a respective one of four color filters 65 over the aperture. Energizing more than one servomechanism will provide a mixture of colors.

A simple electromagnetic actuator satisfactorily operates each filter 65 by swinging the filter in its own plane; and the shutter 63 can be a lightly spring-loaded device pushed aside by engagement of any filter with a shutter bar 68. However,

for very high intensity illumination electromagnetic control of an air jet could be more satisfactory for filter actuation as this jet would not only provide the necessary rapid movement but also keep the filter cool.

The circuit arrangement for one light unit only is illustrated in FIG. 11. The four-color information photoelectric cells 69 and the extra cell 70 for lamp switching are shown all connected over a common line 71 to the four filter actuators 64 and the lamp relay 67. The filter actuators and the lamp relay are all provided on the light unit itself and they are connected to respective coding circuits in an electrical filter box 72 which has a second line 73 returning to the control room. The filter box 72 is also situated on the sign itself and, together with its supply line 73, will be common to a large number of light units. Each of the filter actuators 64 and the lamp relay 67 is provided with a low-voltage DC supply over lines 74.

The purpose of the circuits in the filter box 72 is to make each of the four filter actuators and the lamp relay responsive to a different type of supply signal derived from a basic AC supply. The coding could be as follows:

1. First filter positive half cycle pulses 2. Second filter negative half cycle pulses 3. Third filter positive-going DC 4. Fourth filter negative-going DC 5. Lamp relay half-voltage (or lower) AC In addition, the lamp relay would be arranged to respond to the first four supplies; but would be the only circuit to operate on the fifth supply. Each filter would be responsive to. its own supply only. The first and second supplies would be derived by half-wave rectification of the same AC signal.

This arrangement has the limitation that circuits 3 and 4 cannot be operated together. A more ambitious coding scheme could be devised to meet any case where that was a real difficulty.

As a method of control of the sign alternative to optical projection on to photoelectric cells, the required information could be electromagnetically recorded on tape and read off, shortly in advance of being required, into a matrix store. A trigger pulse could then be employed to cause the matrix store information to light the appropriate lamps. It would desirable to have two stores loaded alternately. Information on tape could in this way readily be used to control signs at a number of different sites by telemetry.

While the invention is not limited to displays provided externally on buildings for advertisement purposes this will be a common application. It will therefore be useful to be able to show the advertising customer the planned display while it is still at the art work or discussion stage. For this purpose, an egg-box-type grid can be employed into which individual blocks can be mounted that have colors on one face (representing the effective color of a single mosaic unit of the display) and code spots on the opposite face. If it is ensured that these blocks only fit into the grid one way up, mosaics can be made which can be photographed at both sides, quickly changed, photographed again, and so on, to build up a film both of the animated display and the corresponding spot coding. Such film can, of course, be subjected to normal film-editing processes, after which the pictorial version of the film can be screened for the advertising customer showing him a close approximation to the final effect of the animated display. Thus the artist simultaneously composes and codes the picture which can afterwards be edited. It will be convenient for the blocks to be removable from and replaceable in the grid in rows at a time, in both directions, since animations commonly change row by row.

What we claim is:

1. An illuminated display system including a display equipment and a control equipment in combination, the display equipment comprising a plurality of lighting units each having an individual illuminable screen and individual rapid colorchanging electric illumination means to illuminate substantially the whole of the respective screen which color-changing illumination means is controllable to rapidly change the color of illumination of the respective screen, the lighting units being placed with their screens together building up a substantially continuous display area in which each individual screen can be illuminated selectively and independently in a choice of colors substantially without causing illumination of its fellows, and the control equipment comprising a matrix of control components which control components can be selectively and individually activated for controlling the illumination means and selecting the colors, there being a respective set of several such control components allotted to each lighting unit and a relay means associated respectively with each control component in the set whereby several individual control outputs are applied to the respective lighting unit, and wherein the illumination means in each lighting unit comprises different color filters movable selectively in front of a single lamp, and the set of control components relating to a particular lighting unit comprises one control components each for controlling the movements of an individual filter.

2. A system according to claim 1, wherein the filters are arranged to move into and out of the light path by swinging in an arc, and a shutter is provided to obturate the light beam which shutter is automatically moved aside whenever a filter swings into its operative position.

3. An illuminated display system including a display equipment and a control equipment in combination, the display equipment comprising a plurality of lighting units each having an individual illuminable screen and individual rapid colorchanging electric illumination means to illuminate substantially the whole of the respective screen which color-changing illumination means is controllable to rapidly change the color of illumination of the respective screen, the lighting units being placed with their screens together building up a substantially continuous display area in which each individual screen can be illuminated selectively and independently in a choice of colors substantially without causing illumination of its fellows, and the control equipment comprising a matrix of control components can be selectively and individually activated for controlling the illumination means and selecting the colors, there being a respective set of several such control components allotted to each lighting unit and a relay means associated respectively with each control component in the set whereby several individual control outputs are applied to the respective lighting unit, and wherein the illumination means in each lighting unit comprises a plurality of lamps behind the screen and having different individual color filters, the screen being translucent, and wherein the control components in the matrix are photoelectric cells selectively activated by projection thereon of images from a film projector, and wherein each film frame has thereon a number of spatially displaced images corresponding respectively to an equal number of different color components of the required display, and the photocells in the matrix are correspondingly grouped so that each said image falls on a group of photocells that controls the lamps in the lighting units of the display for producing that particular color.

4. An illuminated display system including a display equipment and a control equipment in combination, the display equipment comprising a plurality of lighting units each having an individual illuminable screen and individual rapid colorchanging electric illumination means to illuminate substantially the whole of the respective screen which color-changing illumination means is controllable to rapidly change the color of illumination of the respective screen, the lighting units being placed with their screens together building up a substantially continuous display area in which each individual screen can be illuminated selectively and independently in a choice of colors substantially without causing illumination of its fellows, and the control equipment comprising a matrix of control components which control components can be selectively and individually activated for controlling the illumination means and selecting the colors, there being a respective set of several such control components allotted to each lighting unit and a relay means associated respectively with each control component in the set whereby several individual control outputs are applied to the respective lighting unit, and wherein the illumination means in each lighting unit comprises a plurality of lamps behind the screen and having different individual color filters, the screen being translucent, and wherein the control components in the matrix are photoelectric cells selectively activated by projection thereon of images from a cinematographic film projector, and wherein the image on each film frame is in the form of an array of transparent spots set in an opaque background, individual spots allowing light to fall on an individual photocell corresponding to a lamp in the display that is to be switched on, and wherein a spot initiating switching on of a particular lamp occurs in a film frame in advance of the frame bearing the spots which constitute the information representing the next color required from the particular lighting unit in which that lamp is situated. 5. An illuminated display system including a display equipment and a control equipment in combination, the display equipment comprising a plurality of lighting units each having an individual illuminable screen and individual rapid colorchanging electric illumination means to illuminate substantially the whole of the respective screen which color-changing illumination means is controllable to rapidly change the color of illumination of the respective screen, the lighting units being placed with their screens together building up a substantially continuous display area in which each individual screen can be illuminated selectively and independently in a choice of colors substantially without causing illumination of its fellows, and the control equipment comprising a matrix of control components which control components can be selectively and individually activated for controlling the illumination means and selecting the colors, there being a respective set of several such control components allotted to each lighting unit and a relay means associated respectively with each control component in the set whereby several individual control outindependently switched lamps having different color filters and a fourth lamp to give a further color, and a logic circuit mounted on the lighting unit causes the fourth lamp to light, in place of said first three lamps, when switching on of all said first three color lamps is called for by the control equipment.

6. An illuminated display system including a display equipment and a control equipment in combination, the display equipment comprising a plurality of lighting units each having an individual illuminable screen and individual rapid colorchanging electric illumination means to illuminate substantially the whole of the respective screen which color-changing illumination means is controllableto rapidly change the color of illumination of the respective screen, the lighting units being placed with their screens together building up a substantially continuous display area in which each individual screen can be illuminated selectively and independently in a choice of colors substantially without causing illumination of its fellows, and the control equipment comprising a matrix of control components which control components can be selectively and individually activated for controlling the illumination means and selecting the colors, there being a respective set of several such control components allotted to each lighting unit and a relay means associated respectively with each control component in the set whereby several individual control outputs are applied to the respective lighting units, and wherein the relay means are mounted on the respective lighting units, and wherein the relay means are in the case of those of any one lighting unit adapted to respond to different types of electrical supply signal transmitted over a common line. 

1. An illuminated display system including a display equipment and a control equipment in combination, the display equipment comprising a plurality of lighting units each having an individual illuminable screen and individual rapid color-changing electric illumination means to illuminate substantially the whole of the respective screen which color-changing illumination means is controllable to rapidly change the color of illumination of the respective screen, the lighting units being placed with their screens together building up a substantially continuous display area in which each individual screen can be illuminated selectively and independently in a choice of colors substantially without causing illumination of its fellows, and the control equipment comprising a matrix of control components which control components can be selectively and individually activated for controlling the illumination means and selecting the colors, there being a respective set of several such control components allotted to each lighting unit and a relay means associated respectively with each control component in the set whereby several individual control outputs are applied to the respective lighting unit, and wherein the illumination means in each lighting unit comprises different color filters movable selectively in front of a single lamp, and the set of control components relating to a particular lighting unit comprises one control components each for controlling the movements of an individual filter.
 2. A system according to claim 1, wherein the filters are arranged to move into and out of the light path by swinging in an arc, and a shutter is provided to obturate the light beam which shutter is automatically moved aside whenever a filter swings into its operative position.
 3. An illuminated display system including a display equipment and a control equipment in combination, the display equipment comprising a plurality of lighting units each having an individual illuminable screen and individual rapid color-changing electric illumination means to illuminate substantially the whole of the respective screen which color-changing illumination means is controllable to rapidly change the color of illumination of the respective screen, the lighting units being placed with their screens together building up a substantially continuous display area in which each individual screen can be illuminated selectively and independently in a choice of colors substantially without causing illumination of its fellows, and the control equipment comprising a matrix of control components can be selectively and individually activated for controlling the illumination means and selecting the colors, there being a respective set of several such control components allotted to each lighting unit and a relay means associated respectively with each control component in the set whereby several individual control outputs are applied to the respective lighting unit, and wherein the illumination means in each lighting unit comprises a plurality of lamps behind the screen and having different individual color filters, the screen being translucent, and wherein the control components in the matrix are photoelectric cells selectively activated by projection thereon of images from a film projector, and wherein each film frame has thereon a number of spatially displaced images corresponding respectively to an equal number of different color components of the required display, and the photocells in the matrix are correspondingly grouped so that each said image falls on a group of photocells that controls the lamps in the lighting units of the display for producing that particular color.
 4. An illuminated display system including a display equipment and a control equipment in combination, the display equipment comprising a plurality of lighting units each having an individual illuminable screen and individual rapid color-changing electric illumination means to illuminate substantially the whole of the respective screen which color-changing illumination means is controllable to rapidly change the color of illumination of the respective screen, the lighting units being placed with their screens together building up a substantially continuous display area in which each individual screen can be illuminated selectively and independently in a choice of colors substantially without causing illumination of its fellows, and the control equipment comprising a matrix of control components which control components can be selectively and individually activated for controlling the illumination means and selecting the colors, there being a respective set of several such control components allotted to each lighting unit and a relay means associated respectively with each control component in the set whereby several individual control outputs are applied to the respective lighting unit, and wherein the illumination means in each lighting unit comprises a plurality of lamps behind the screen and having different individual color filters, the screen being translucent, and wherein the control components in the matrix are photoelectric cells selectively activated by projection thereon of images from a cinematographic film projector, and wherein the image on each film frame is in the form of an array of transparent spots set in an opaque background, individual spots allowing light to fall on an individual photocell corresponding to a lamp in the display that is to be switched on, and wherein a spot initiating switching on of a particular lamp occurs in a film frame in advance of the frame bearing the spots which constitute the information representing the next color required from the particular lighting unit in which that lamp is situated.
 5. An illuminated display system includiNg a display equipment and a control equipment in combination, the display equipment comprising a plurality of lighting units each having an individual illuminable screen and individual rapid color-changing electric illumination means to illuminate substantially the whole of the respective screen which color-changing illumination means is controllable to rapidly change the color of illumination of the respective screen, the lighting units being placed with their screens together building up a substantially continuous display area in which each individual screen can be illuminated selectively and independently in a choice of colors substantially without causing illumination of its fellows, and the control equipment comprising a matrix of control components which control components can be selectively and individually activated for controlling the illumination means and selecting the colors, there being a respective set of several such control components allotted to each lighting unit and a relay means associated respectively with each control component in the set whereby several individual control outputs are applied to the respective lighting unit, and wherein the illumination means in each lighting unit comprises three independently switched lamps having different color filters and a fourth lamp to give a further color, and a logic circuit mounted on the lighting unit causes the fourth lamp to light, in place of said first three lamps, when switching on of all said first three color lamps is called for by the control equipment.
 6. An illuminated display system including a display equipment and a control equipment in combination, the display equipment comprising a plurality of lighting units each having an individual illuminable screen and individual rapid color-changing electric illumination means to illuminate substantially the whole of the respective screen which color-changing illumination means is controllable to rapidly change the color of illumination of the respective screen, the lighting units being placed with their screens together building up a substantially continuous display area in which each individual screen can be illuminated selectively and independently in a choice of colors substantially without causing illumination of its fellows, and the control equipment comprising a matrix of control components which control components can be selectively and individually activated for controlling the illumination means and selecting the colors, there being a respective set of several such control components allotted to each lighting unit and a relay means associated respectively with each control component in the set whereby several individual control outputs are applied to the respective lighting units, and wherein the relay means are mounted on the respective lighting units, and wherein the relay means are in the case of those of any one lighting unit adapted to respond to different types of electrical supply signal transmitted over a common line. 